require('font-icon');

/**
 * Applies a font icon to an element.
 *
 * @param {list/string} $glyph
 * A unicode character to use as the icon, or a list specifying the character to use
 * followed by font-size, font-family, and degrees of rotation (90, 180, or 270).
 * All parameters in the list are optional except for glyph.  For example, each of the
 * following is valid:
 *
 * Use the letter "A" as the icon, inherit the font-size from the parent element,
 * and use the default font-family specified by {@link Global_CSS#$font-icon-font-family}.
 *
 *     .my-icon {
 *         @include font-icon('\0041');
 *     }
 *
 * Use the letter "A" as the icon with a font-size of 16px, and the default font-family
 *
 *     .my-icon {
 *         @include font-icon('\0041' 16px);
 *     }
 *
 * Use the letter "A" as the icon, inherit font-size, and use FontAwesome as the font-family
 *
 *     .my-icon {
 *         @include font-icon('\0041' FontAwesome);
 *     }
 *
 * Use the letter "A" as the icon, inherit font-size, use the default font-family, and rotate
 * the icon 90 degrees clockwise.
 *
 *     .my-icon {
 *         @include font-icon('\0041' 90);
 *     }
 *
 * Use the letter "A" as the icon with a 16px font-size, and a FontAwesome as the font-family.
 *
 *     .my-icon {
 *         @include font-icon('\0041' 16px FontAwesome);
 *     }
 *
 * Use the letter "A" as the icon with a 16px font-size, default font-family, and rotate
 * the icon 90 degrees clockwise.
 *
 *     .my-icon {
 *         @include font-icon('\0041' 16px 90);
 *     }
 *
 * Use the letter "A" as the icon, inherit the font-size, use FontAwesome as the font-family,
 * and rotate the icon 90 degrees clockwise.
 *
 *     .my-icon {
 *         @include font-icon('\0041' FontAwesome 90);
 *     }
 *
 * Use the letter "A" as the icon with a font-size of 16px, use FontAwesome as the font-family,
 * and rotate the icon 90 degrees clockwise.
 *
 *     .my-icon {
 *         @include font-icon('\0041' 16px FontAwesome 90);
 *     }
 *
 * NOTE: Only numeric values with units are accepted for font-size, e.g. `16px` or `2em`.
 *
 * @param {boolean/string} [$pseudo=true]
 * By default this mixin generates a "before" pseudo element ruleset to contain the icon.
 * Set this parameter to "after" to use an after pseudo element.  Set to `false` if you are
 * invoking the font-icon() mixin from within a pseudo element ruleset.
 *
 * @param {number} [$line-height=1]
 * Optional line-height to apply to the icon.
 * Pass `null` to avoid setting line-height and inherit from parent element.
 *
 * @param {color} $color
 * Optional color for the glyph.
 *
 * @param {boolean} [$style-pseudo=false]
 * By default, font and color styles are placed on the icon-containing element, not the
 * pseudo.  This allows for easier customization of font-icons by users since many
 * font-icon generators also place the font styles on the containing element.
 * Set this to `true` to set font and color styles on the pseudo element instead.  This
 * is necessary in cases where the icon-containing element is not exclusively dedicated
 * to containing the icon and may contain other text as well, for example, grid headers
 * and grid grouping headers.
 * 
 * @member Global_CSS
 * @private
 */
@mixin font-icon($glyph, $pseudo: true, $line-height: 1, $color: null, $style-pseudo: false) {
    $args: parseFontIconArgs($glyph);

    $char: nth($args, 1);
    $font-size: nth($args, 2);
    $font-family: nth($args, 3);
    @if $font-family == null {
        $font-family: $font-icon-font-family;
    }
    $angle: nth($args, 4);
    $rotation: null;
    $rotation-origin: 50% 50%;
    $ie-rotation: null;

    @if $angle != null {
        $rotation: rotate(#{$angle}deg);
        @if $angle == 90 {
            $ie-rotation: 1;
        } @else if $angle == 180 {
            $ie-rotation: 2;
        } @else if $angle == 270 {
            $ie-rotation: 3;
        }
    }

    @if $char != null {
        @if $pseudo == false {
            @include font-icon-pseudo-content($char, $rotation, $rotation-origin);
            @include font-icon-style($font-size, $line-height, $font-family, $color);
        } @else {
            @if not $style-pseudo {
                @include font-icon-style($font-size, $line-height, $font-family, $color);
            }

            @if $pseudo == before or $pseudo == true {
                &:before {
                    @include font-icon-pseudo-content($char, $rotation, $rotation-origin);
                    @if $style-pseudo {
                        @include font-icon-style($font-size, $line-height, $font-family, $color);
                    }
                }
            } @else if $pseudo == after {
                &:after {
                    @include font-icon-pseudo-content($char, $rotation, $rotation-origin);
                    @if $style-pseudo {
                        @include font-icon-style($font-size, $line-height, $font-family, $color);
                    }
                }
            }
        }

        @if ($rotation != null) and $pseudo and $include-ie {
            // IE8 does not support filters on pseudo elements, so we have to rotate the
            // containing element instead of the pseudo element
            .#{$prefix}ie8 & {
                -ms-filter: "progid:DXImageTransform.Microsoft.BasicImage(rotation=#{$ie-rotation})";
            }
        }
    }
}

@mixin font-icon-style($font-size, $line-height, $font-family, $color) {
    @if $font-size != null {
        @if $line-height != null {
            font: #{$font-size}/#{$line-height} $font-family;
        } @else {
            // use separate properties for font-size and font-family so that line-height
            // will be preserved from prior font declarations
            font-size: $font-size;
            font-family: $font-family;
        }
    } @else {
        font-family: $font-family;
        line-height: $line-height;
    }
    color: $color;
}

@mixin font-icon-pseudo-content($char, $rotation, $rotation-origin) {
    content: $char;

    @if $rotation != null {
        display: inline-block;
        -webkit-transform: $rotation;
        -webkit-transform-origin: $rotation-origin;
        -moz-transform: $rotation;
        -moz-transform-origin: $rotation-origin;
        -ms-transform: $rotation;
        -ms-transform-origin: $rotation-origin;
        transform: $rotation;
        transform-origin: $rotation-origin;
    }
}
